Air conditioner

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Solution Overview

Problem

Existing air conditioner technologies do not effectively separate refrigerant by flow pattern inside an evaporator, leading to potential damage to the compressor and reduced reliability.

Innovation Solution

The air conditioner superheats a refrigerant separated by a flow pattern inside an evaporator, using a subcooler and a gas-liquid separator to control the degree of superheat, thereby preventing liquid refrigerant from entering the compressor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If refrigerant is not separated by flow pattern inside evaporator, then device complexity is reduced, but compressor reliability deteriorates due to liquid refrigerant damage

Engineering Contradiction:
Improvecompressor reliabilityVSAvoidevaporator structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The evaporator is divided into multiple flow patterns (annular flow, stratified flow, mist flow) with different refrigerant separation characteristics. By segmenting the evaporator into distinct flow pattern zones, the system can identify and separate liquid refrigerant from gas refrigerant based on the specific flow pattern occurring in each zone, thereby protecting the compressor from liquid damage while maintaining manageable structural complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A refrigerant separation degree calculation unit acts as an intermediary that calculates the degree of refrigerant separation based on flow pattern information. This intermediary component processes the complex flow pattern data and converts it into actionable control signals for the expansion valve, enabling compressor protection without requiring direct complex mechanical separation structures in the evaporator.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If refrigerant flow velocity is increased to improve heat exchange efficiency, then productivity is improved, but refrigerant separation control becomes more difficult

Engineering Contradiction:
Improveheat exchange efficiencyVSAvoidflow pattern detection difficulty
Core Design Contradiction:
ProductivityVSDifficulty of detecting and measuring

Solution Approach 1:

The system implements feedback control by continuously detecting refrigerant flow velocity and flow pattern characteristics, calculating the degree of refrigerant separation, and adjusting the expansion valve opening degree accordingly. This feedback mechanism enables the system to maintain optimal heat exchange efficiency while dynamically adapting to varying flow conditions that affect refrigerant separation, making high-velocity operation controllable and reliable.

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution prevents compressor damage and improves the reliability of the air conditioner by ensuring that only gas refrigerant is introduced into the compressor, enhancing the overall performance and efficiency of the system.

Implementation Method 1

a subcooler and a gas-liquid separator to control the degree of superheat

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

a subcooler and a gas-liquid separator to control the degree of superheat, thereby preventing liquid refrigerant from entering the compressor

Methodology Applied
Scientific EffectGas-liquid separation: Density Gradient

Implementation Method 3

the indoor heat exchanger functions as an evaporator

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP3889519B1Air conditioner
Publication Date: 2025.04.23 LG ELECTRONICS INC
  • EP3889519B1 patent drawingFigure 1
  • EP3889519B1 patent drawingFigure 2
  • EP3889519B1 patent drawingFigure 3

AI summary

Provided is an air conditioner including a connection pipe (321) connected to a refrigerant pipe disposed inside an outdoor heat exchanger (309) that operates as a condenser during a cooling operation and as an evaporator during a heating operation, a header (323) connected to the connection pipe, wherein a refrigerant separated from a two-phase refrigerant flowing through the refrigerant pipe flows through the header (323), a bypass pipe (325) connected to the header to guide a flow of the refrigerant to a compressor (301), a flow rate control valve installed at the bypass pipe to control a flow velocity of the refrigerant, a subcooler (307) configured to superheat the refrigerant flowing through the bypass pipe, and a controller configured to control an opening degree of the flow rate control valve.